1. Field of the Invention
The present invention relates to an image forming apparatus including a toner recovering mechanism, such as a printer, a copier, or a facsimile.
2. Description of the Related Art
In an image forming apparatus based on an electrophotographic system, toner is delivered between units such as a toner container, a hopper container, a development device, a drum cartridge, and a recovery toner container. Here, the delivery of toner to the recovery toner container will be described as an example.
A residual transfer toner is removed and discharged by a cleaning portion from an electrophotographic photosensitive body or an intermediate transfer member after image formation. On the other hand, as for two-component developers in the development device, old developers are gradually discharged in order to prevent charging performance degradation.
The residual transfer toner or the discharged two-component developers are conveyed by a toner conveying mechanism to a discharge port and then are recovered through the discharge port into the recovery toner container. When a toner recovery amount in the recovery toner container reaches a predetermined amount, the recovery toner container is replaced with a new empty recovery toner container.
The recovered toner may leak through a gap in a connection portion between the discharge port and a recovering port of the recovery toner container. In order to prevent such leakage, the following technique is suggested (see Japanese Patent Laid-Open No. 2005-156699).
In Japanese Patent Laid-Open No. 2005-156699, a foam material (sponge) is provided at a discharge port or a recovering port of a recovery toner container, and the foam material is sandwiched and crumpled between the discharge port and the recovering port of the recovery toner container to seal a gap therebetween. This prevents leakage of the recovered toner.
However, when the recovery toner container disclosed in Japanese Patent Laid-Open No. 2005-156699 is moved in a direction perpendicular to a sponge compression direction as illustrated in FIG. 9A, a surface of the sponge being the connection portion between the discharge port and the recovering port is compressed. Therefore, the recovering port may not be sealed by wrinkling or curling of the sponge. In this case, the toner leaks from the gap between the discharge port and the recovering port.
Here, if the recovery toner container is moved in the sponge compression direction as described in FIG. 9B of Japanese Patent Laid-Open No. 2005-156699, wrinkling and curling of the sponge can be suppressed. However, the recovery toner container increases in size in a vertical direction of the image forming apparatus. Also, it is required to provide a complex mechanism such as a pressing mechanism or a holding mechanism for preventing the recovery toner container from falling by gravity.
It is desirable to suppress a deformation of a sealing member in unit attachment/detachment with a simple configuration and to prevent leakage of toner in a toner delivering portion.